Anthropogenic emissions from industry, traffic, households and agriculture affect air quality and contribute to globally increasing greenhouse gas concentrations. Our group specializes in the application of Lagrangian and Eulerian atmospheric models as well as in air pollution remote sensing. We aim to better understand processes governing atmospheric trace gas and aerosol concentrations to answer environmentally pressing questions and to support policy makers. In particular, we focus on

• Quantifying greenhouse gas emissions (halocarbons, CH₄, CO₂, etc.) using inverse methods
• Simulating the effect of specific sources and future scenarios on air pollution levels
• Understanding atmospheric processes (transport, chemistry, air quality – climate interactions)
• Investigating air pollution using satellite and airborne remote sensing

Lagrangian models are powerful tools to simulate atmospheric transport. We apply and further develop Lagrangian Particle Dispersion Models (LPDMs) to study the transport and sources of non- or weakly reactive trace gases including long-lived greenhouse gases. Our main tool is FLEXPART which is applied in a range of different configurations on scales ranging from regional to global.

Read more on our Lagrangian modeling, or visit

• Studies of station representativeness in project GEOMON
• Dispersion of the volcanic ash cloud of Eyjafjallajökull
• Deposition of degradation products of new halocarbons in Europe
• Global FLEXPART simulations of methane in projects LORAT and URMEL

Models describing the full complexity of chemical and physical processes in the atmosphere are usually formulated in a Eulerian framework (fixed grid in space and time). To study air quality and its interactions with meteorology and climate at the regional scale we employ the model COSMO-ART developed at the Karlsruhe Institute of Technology (KIT). These activities are closely linked to the Centre for Climate Systems Modeling (C2SM) of the ETH domain.

Read more on Eulerian modeling, or visit our

• Modeling system and developments
• Preprocessing of boundary conditions and emission inventories
• Evaluation of COSMO-ART

Satellite remote sensing has revolutionized our understanding of global air pollution since the first observations from the UV/VIS spectrometer GOME became available in 1995. We develop satellite retrievals of tropospheric nitrogen dioxide (NO₂) columns tailored at observing regional air pollution. In addition, we analyze measurements from the airborne hyperspectral sensor APEX to map NO₂ pollution sources at scales of a few tens of meters.

• Empa OMI NO₂ (EOMINO) product, providing high-quality NO2 columns for Europe through an advanced treatment of surface reflectance anisotropy and surface pressure in the retrieval.
• MERIS albedo climatology for cloud and trace gas retrievals
• High resolution mapping of NO₂ pollution with airborne spectrometer APEX in project HyperSwissNet
• Validation of CO₂ and CH₄ satellite products in ESA project GHG CCI

We apply inverse methods in combination with trace gas observations and transport models to quantify and allocate emissions. As an example, European halocarbon emissions are inferred from observations at Jungfraujoch in the project Halclim.

Read more ..